Clockwork-operated time fuse



Aug. 10, 1948.

Filed June 22, 1942 F. DELAY CLOCKWORK OPERATED TIME FUSE 6 Sheets-Sheetl Aug. 10, 1948. F. DELAY CLOCKWORK OPERATED TIME FUSE 6 Sheets-Sheet 2Filed June 22, 1942 Aug. 19, 1948. E Y 2,446,745

CLOCKWORK OPERATED TIME FUSE Filed June 22, 1942 6 Sheets-Sheet 3 Aug.10, 1948. F. DELAY 2,446,745

CLOCKWORK OPERATED TIME FUSE Filed June 22, 1942 6 Sheets-Sheet 4 Aug.10, 1948. DELAY 2,446,745

CLOCKWORK OPERATED TIME FUSE 6 Sheets-Sheet 5 Filed June 22, 1942 Aug.10, 1948. F. DELAY 2,446,745

CLOCKWORK OPERATED TIME FUSE Filed June 22, 1942 6 Sheets-Sheet 6Patented Aug. 10, 1948 UNITED STATES PATENT @FFICE CLOCKWORK-OPERATEDTIME FUSE Fernand Delay, Geneva, Switzerland Application June 22, 1942,Serial No. 448,026 In Switzerland June 20, 1941 6 Claims. 1

This invention relates to improvements in means for setting mechanicaltime fuses for projectiles and more particularly to time fuses of thekind wherein the setting operation is effected by unrestrained rotationof the setting member in either direction from the zero position.

Some of the time fuses under consideration usually comprise a clockworkrigidly mounted in the fuse body while in other fuses the clockwork isrotatably mounted within the setting cap of the fuse to rotate with thiscap during the setting operation and to rotate alone after firing withinsaid cap under the driving action of a motor.

According to an important feature of the invention the clockwork casingincluding the motor, the rotary timing member and the escapement andspring regulator, is mounted rotatably in the fuse body and is providedwith means for coupling it to the setting member so that during thesetting of the fuse said clockwork rotates as a whole block within saidfuse for previously setting the time for the burst, while after firingit is locked by means released at the time of firing so that only therotating timing member is allowed to further rotate under the action ofthe motor for causing detonation at a predetermined time.

Another object of the invention is to provide means adapted to insurereliable working of the fuse and increase the safety thereof against anydamage or untimely action especially of the escapement regulator and ofthe percussion members during the carriage, during the acceleration ofthe projectile and during the flight thereof.

A further object of the invention is to provide means whereby the powerfor driving the clockwork may be increased to a maximum extent at leastat the beginning of the flight.

Other and further objects and advantages of the invention will behereinafter set forth and the novel features thereof defined by theappended claims.

In the drawing:

Fig. 1 is an axial sectional view on an enlarged scale with parts inelevation of a first single acting fuse, showing the various members intheir normal position of rest;

Figs. 2, 3 and 4 are fragmentary transverse sectional views on anenlarged scale on the line A--A of Fig. 1 showing the release mechanismin position of rest and in two distinct positions after the settingoperation respectively;

Fig. 5 is a transverse sectional view on an enlarged scale of theclockwork on the line B-B- of Fig. 1;

Fig. 6 is a top plan View of the clockwork from the line C--C of Fig. 1;

Fig. '7 is an elevation of the clockwork;

Fig. 8 is an elevation of the base of the time percussion mechanism;

Fig, 9 is an elevation of the setting key of the fuse;

Fig. 10" is an axial sectional view on an enlarged scale of a secondsingle and double acting fuse;

Fig. ll is a transverse sectional view on the line DD of Fig. 10;

Fig. 12 is an axial sectional view on an enlarged scale of a thirdcentrifugally actuated and high-sensitive percussion fuse showing thevarious members in position of rest before the fir- Fig. 13 is a topplan view of the clockwork showing a part of the high-sensitivepercussion device operated by direct impact of the fuse point onthe-target;

Figs. 14, 15 and 16 are transverse sectional views on the line E-E ofFig. 12 showing the centrifugally actuated driving mechanism in positionof rest before the firing. at the beginning of the flight of theprojectile and during this flight, respectively;

Fig. 17 is a transverse sectional view on the line F--F of Fig. 12showing the time percussion members in safety position before thefiring.

Fig. 18 is an elevation of the clockwork;

Fig; 19 is an elevation of the base of the time percussion mechanism;

Fig. 20 is a plan view of the centrifugal inwardly toothed sector; a

Fig. 21 is a plan view of the centrifugal starting lever acting at thebeginning of the flight for momentarily increasing the power driving theclockwork;

Fig. 22 is an axial sectional view on an enlarged scale with parts inelevation of a further centrifugally operated and high sensitive timefuse embodying the invention, for use in projectiles for small-calibreautomatic guns;

Fig. 23 is an elevation of the fuse shown in Fig. 22;

Fig. 24 is an elevation of the setting key provided with a lockingmechanism acting at the time of firing and during the flight of theprojectile;

Fig. 25 is an elevation of the clockwork shown in Fig. 22

Fig. 26 is an elevation of the base carrying the time percussionmechanism shown in Fig. 22.

The single acting fuse shown in the figures 1 to 6 comprises thefollowing parts: the fuse body made in one piece designated I to Ii; thesetting device mounted on the fuse body, the members of which aredesignated 2 to I; the locking device of the timing position acting atthe time of the firing, mounted on the fuse body I, the members of whichare designated 8 to 8d; the clockwork, the members of which aredesignated II) to 4| e; the percussion device, the members of which aredesignated 42 to 53d; the base plug 9 adapted to maintain into place theclockwork and the base holding the mechanism against the inertia at thetime of firing.

The fuse body I is made in one piece integral with its ogive and thethreaded base Ih; on this body there is frictionally mounted the settingdevice which comprises: a key 2 having a flange 20., the lower face ofwhich is provided with a diametral slot 22) which constitutes the femaleelement of a so-called screwdriver clutch; a spring-washer 3 of hardenedsteel interposed between the flange 2a and a washer bearing on thebottom of the recessed upper part of the body I; a conical cap 5 havingits top end formed with teeth 5a meshing with corresponding longitudinalflutings 2c of the key 2; a notch 5c for turning said cap; a jointclamping ring 5 formed with inner teeth 6a meshing with the flutings 2cof the key 2; a cap nut I screwed on the threaded top end 2d of the key,and finally, three packing rings I0, 5?), 61) made of elastic material,interposed between the top end of the body I and the cap nut 1 so as tocause spring-washer 3 to put a strong pressure on said packing ringsupon tightening of the cap nut, in order to simultaneously secure thetightness of the point of the fuse and a suflicient friction between thefuse body and the setting members to avoid any untimely disturbance ofthe timing position during the manipulations before the firing.

The locking device of the timing position which is also mounted on thefuse body I and acts at the time of firing, comprises a set of segments8 interposed between the conical cap 5 and a cylindrical portion Ie ofthe body I which is embraced by these segments. The segments 8 aremaintained in position by a split-ring 8c lodged in a groove 8b; a stop8d projecting from the wall of each segment 8 is engaged in acorresponding recess I d of body I, so that segments 8 and body I arecoupled in rotation with each other; segments 8 are also shown having aconical annular surface 8a which cooperates with a corresponding conicalshoulder If on the fuse body I to cause spreading out of the segments 8upon firing by inertia under the action of the linear accelerationforce.

The casing of the clockwork, which is loosely mounted in the body I,comprises two parts, namely: a lower part In and an upper part I3 whichare fitted one within the other by their adjacent surfaces in and I 3aand made angularly dependent on each other by means of a stud I30 forcedin corresponding mortises of the parts I III and I3. These parts form, arigid assembly containing the clockwork and adapted to freely rotate inthe body during the setting operation.

In the lower casing part ID are housed the following members: thedriving spiral spring II bearing on a washer I which constitutes thebottom of the barrel; a hook Illa with which engages the eyelet I lb ofthe free end of the driving spiral spring II; a safety and stop lever I2with its spring [2d, which lever is pivoted within a recess Ifid about apin I lie forced in the side wall of the casing part II]; the lever I2,the double function of which will be hereinafter disclosed, has its longarm I2a intended as a pawl for setting to a maximum extent the spiralspring II, by engaging a notch Md of the control crown GI of the releasemechanism; this crown 4| is in gearing relation with the teeth 39a ofthe driving shaft 39 through a gear 40 journalled on a stud 40a securedto the washer I Dc. Driving shaft 39 comprises a bush 390 made angularlyrigid with it by means of a split pin 39d which also constitutes thehook engaging the eyelet IIa of the driving spiral II. Crown 4| ismounted on a ball bearing 4Ia.

Driving shaft 39 comprises at its upper end a gear wheel 3% whichconstantly meshes with the first pinion 38 of the gear train of theclockwork and has its lower end formed with a firing pin 39c. I4 is acap bearing on which is journalled the rounded end of the lower pivot29b of the balance staff 29; I is the base plate of the clockwork; I5 isan auxiliary plate or bridge to which is secured the bearing I! for theescape wheel SI and the gear train; I8 is a pillar for assembling boththe base and the auxiliary plates with casing part I3; I9 is a spacingring carrying the intermediate plate 2| is a second spacing ringcarrying the upper plate 22; 22a is a catch made integral with the upperplate 22; catch 22a engages in a slot of the casing wall to make theupper plate 22 angularly rigid with the casing part I3. 221) is a recessin the upper plate 22, the function of which will be hereinafterdisclosed; 23 designates two spring-pressed centrifugal leversjournalled on upstanding studs 26 on plate 22 for locking the balancewheel before firing by means of locking pins 23a which pass through anopening 220 in the upper plate 22 and co-operate with the arms 30a ofthe balance wheel. 25 is a bar secured to the upper plate 22 by means oftwo rivets 26. Bar 25 has a double function: on one hand it cooperateswith slot 2b of setting key 2 as the male element of the screwdriverclutch interposed between said setting key and the bar 25 for couplingthe clockwork with the setting members 2, 5; bar 25 is intended on theother hand to support by its threaded portion 25a a tube 21 housed inthe central bore 2e of the setting key 2; 21a designates a slit in whichcatch 21b of the threaded slide 270 is movably arranged and engages anut (not shown) lodged in the interior of the tube 27, for adjusting theoperative length of a torsion leaf 28 located in the interior of saidtube 21; this torsion leaf constitutes the adjusting member of thebalance wheel with which it is connected by means of a ferrule 28asecured to the upper pivot 29a of the balance staff 29. 32 is the usualbevel pinion of the escape wheel 3I; 33 is a bevel wheel, 34 a pinion,35 a wheel and 36 a pinion of the gear train (Fig. 5).

The time percussion device of the fuse shown in Figs. 1 to 4 is locatedimmediately underneath the clockwork with which it co-operates.

It comprises the following elements: a mechanism holder designated 42comprising: two split pins 42a, a long guiding sleeve 42b provided witha groove 42c and two radial holes 42d, the lower end of said sleevebeing inwardly threaded at 42c; a primer holder 43 slidably mounted inthe sleeve 42b; 43a the primer; 4317 a washer for fastening the primer43a; washer 43b is set at 430; two diametrically opposed sockets 43a inthe sliding primer holder 43; a percussion spring 44; a release lever 45with a toe 45a and a wider portion 45b provided with a guiding notch 45cco-operating with a pin 46 forced in the base 42, which pin serves tofix the angular position of the release lever 45; two locking balls 4'5engaged in the sockets 43d of the percussion cap holder 43 through theholes 42d of the guiding sleeve 4% and held in operative lockingposition by means of a bush 49 slidably mounted on the sleeve 42?) andurged upwards by a spring 49; bush 48 is provided at its upper end withan internal groove 43a adapted to co-operate after firing with a lockingsegment 55 for the sleeve 42b; 5| designates a threaded cap plug screwedin the lower end 426 of sleeve 42b, on which bears the percussion spring44; 52 is a plate made angularly rigid with the base 42 by means of thepins 42a and having a catch 52a engaged in the corresponding mortise orslot in provided in the inner wall of the fuse body i for fixing therelative angular position of base 42 and body H. 53 is a plate, theangular position of which 'in relation to plate 52 and base 42 is alsofixed by means of the pins 42a; plate 53 is formed with a small catch5301, which co-operates in the safety position of the fuse with a fiatlug |2c of lever l2 to prevent this lever from swinging before thesetting operation; 531) is a circular cam surface the radius of which issmaller than the radius of the catch 53a in order to permit oscillationof the lever if by leaving a free space necessary to the effacement ofthe rounded end of the small lever arm |2b after setting of the fuse(Figs. 3 and 4) 53c designates two small curves connecting the circularcam surface 53b with the top of catch 53a; said curves are Tntended tocause the fiat lug |2c of the lever arm |2b to rise over the catch 53aby swinging the lever |2 when the fuse is brought back to the safetyposition after setting; 53d designates an opening having the shape ofthe release lever 45 with a play sufiicient to prevent any friction withthis lever.

The base 42 which is larger in diameter than plates 52 and 53 ismaintained into place in its recess in fuse body l by means of athreaded plug 9, on the bottom of which bears the safety spring 49. Aradial screw 9a is intended to lock plug 9.

A modified construction of the improved fuse of Figs. 1 to 6 is shown inFigs. and 11. In this modification all members or parts for which nospecial mention will be made hereinafter are similar to thecorresponding members or parts of the first construction.

The control member of the time percussion mechanism is formed rigid withthe bush 4| f and the crown 4'| which both turn about a fixed hollowspindle |3i made rigid with the upper casing part l3, so that crown 4|merely effectuates one revolution during the maximum working period ofthe clockwork.

The firing pin 51 with its spring 58 is mounted axially movable in thehollow shaft I31 and the percussion mechanism inertia.

Referring to the drawing, 91) designates an is double acting by 551) forthe passage of the firing pin 51 at the time of releasing thepercussion; 55c designates a conical semi-circular notch out out in therim of the opening 55b and which in co-operating with a correspondingconical shoulder 51a on firing pin 51 holds the latter in tensionedposition against the action of the percussion spring 58 55d designates aboss adapted to compensate toa certain extent for the centrifugal forcewhich acts at the opposite side of the nose 55a and thus tosubstantially reduce the friction of this nose on the inner wall of drumMe; 55a is a hole in the lever 55, in which a safety pin 6| engagesbefore firing; 51b is a cylindrical shoulder onfiring pin 51, whichshoulder co-operates with a corresponding opening 5% extending througha'safety lever 59 lodged in the opening 52b of plate 52; lever 59 has afork shaped opening 59a through which extends the point of the firingpin 51; safety pin 9| is also intended to hold in operative position thesafety lever 59' which oscillates like lever 55 about a stud 56. 590 isa split pin fixed on lever 59 and intended to hold in operative positiona safety ball 63 placed between the upper end of a primer holder 62 andthe rear face of lever 59; 60 designates an auxiliary locking pin oflever 55 which is guided like safety pin 6| in an opening provided inthe base 42 and both the plates 52 and 53. Primer holder 62 which isguided in the sleeve 42b of the base 42 is also locked prior to thefiring in the same manner as the sliding primer holder 43 of the firstconstruction, namely by means of two balls 4! held in place by bush 48and spring 49 hearing on the bottom of base plug 9 which also serves tomaintain the base 42 in place in the fuse body I.

In operation of the first fuse shown in Figs. 1 to 6 and abovedescribed, it will be noted that in position of rest, as shown in Figs.1, 2 and 6, the following members locking the fuse are in operativeposition: the sliding primer holder 43 is held away from the firing pin39c against the action of spring 44 by the two balls 4! which are heldin looking position by the bush 48 located under the action of spring49; driving spiral spring I! is provided at the factory, with apredetermined tension which is sufficient to rotate the driving shaft 39by several revolutions while crown 4| turns through a smaller ang-lethan 360 owing to the reduction gear ratio between said shaft 39 andcrown 4|. Spiral spring H is maintained in tensioned condition by thelong lever arm In which serves as a retaining pawl by leaning throughnotch 4|d against the wall of crown 4|; lever I2 is held in the positionshown in Figs. 1 and 2, by its spring IM and is prevented from untimelyswinging by the safety catch 53a which is located midway the fiat lug|2c on the rounded end of the small arm I2b.

In that position, the rounded end of the small arm |2b is located midwaythe slot |a of the body and the free space formed by the slotconstitutes the dead angle through which lever |2 cannot untimely swing.

The spring-pressed stop levers 23 lock the balance wheel 30 by means oflocking pins 23a which engage the arms 30a thereof; balance wheel 30cannot therefore oscillate as long as said levers 23 are held in theposition shown in Figs. 1 and 6. Moreover the locking of the balancewheel 30 constitutes a mean for preventing any untimely retrogression ofthe driving power like the stud I30 which renders casing part angularlyrigid with casing part l3.

When setting the fuse, the clockwork casing is rotated by the key 2through the medium of the screw driver clutch 2b, so that lever I2 iscaused to oscillate when the rounded end of the small lever arm [2bmeets with the wall of the fuse body I and on the other hand notch Mdand thus crown 4| is released.

Figs. 3 and 4 show the position of lever I2 after a long and a shorttiming respectively.

In both such positions notch 41d is displaced through a certain angle intwo opposite directions with respect to the release lever 45, theangular position of which is fixed by means of the guiding pin 46co-operating with the corresponding notch 450.

At the time of firing, the segments 8 for locking the timing positionspread out by inertia owing to the co-operation of the conical portionsIf and 8a and put a heavy lateral pressure on the inner wall of cap 5thus preventing any untimely angular displacement of the latter, thelocking of said cap being so secured not only during longitudinalacceleration of the projectile in the bore of the gun, but also duringthe flight of the projectile under the effect of the centrifugal force.

Simultaneously the bush 48 runs down by inertia compressing spring 49and becomes immediately locked by the segment 50 which spreads outthrough the corresponding groove 48a of bush 48. Immediately aftercomplete linear acceleration, the centrifugal force projects out balls41 from their sockets and spring 44 immediately repels the slidingprimer holder 43 thus driving the release lever 45 with its toe 45aagainst the circular rim of the crown 4 I.

The levers 23 driven by the centrifugal force, release balance wheelfrom pin 23a; balance wheel 30 immediately oscillates under the effectof the driving power actuating the gear wheels and the escape Wheel, theoscillations of which are regulated by the vibrations of the torsionleaf 28.

The control crown 41 immediately begins to rotate in a clockwisedirection as viewed in Figs. 3 and 4 and when notch 4ld comes to lie infront of release toe 45a, percussion spring 44 suddenly urges up theprimer holder 43 through said notch, thus causing percussion of theprimer 43a against the firing pin and consecutive explosion of theprojectile.

In the second embodiment shown in Figs. 10 and 11, the process isidentical except for the percussion mechanism which works as follows:The fuse is set in the same manner as in the first describedconstruction at a predetermined time so that notch Md and nose 55a ofthe release lever 55 become relatively displaced.

At the time of firing, bush 48 runs down by inertia thus compressingspring 49 and being immediately locked in this position by segment 50.Simultaneously safety pins BI and 60 also run off by inertia thusreleasing release lever 55 and safety lever 59 respectively, releaselever is still retained by drum 41 whilst the safety lever swings underthe effect of the centrifugal force, thus permitting escape of safetyball 63 into its recess 42/.

Simultaneously, the clockwork begins to rotate as above described andwhen notch 41d of drum 4| comes to lie in front of the end of nose 55a,lever 55 under the combined action of the centrifugal force and of thepercussion spring and owing to co-operation of the conical portions 550and 51a suddenly oscillates for allowing firing pin 51 to pass throughthe opening 55b for striking the primer 43a. However, if the projectilecollides with an obstacle during its flight before the predeterminedtime of detonation, primer holder 62 is allowed to run upwards byinertia against the firing pin 5! for igniting the charge at the time ofimpact. During the flight, the primer holder may be retained away fromthe firing pin by any suitable means, for example by a stop spring or byfriction.

It will be noted that the lower face of bar 25 is so recessed as toclear the centre of the plate 22 and that the latter has a thinner part221) in order to avoid excessive reaction on staff 29 of balance wheel3.0 when the plate is deflected at the time of the firing, thus avoidingany injurious strain on this important regulating member.

In the embodiment shown in Figs. 12 to 21, the fuse differs from thefirst one in that it comprises 1. A centrifugal device for actuating theclockwork lodged in a casing made in one piece.

2. A high-sensitive percussion device housed in the point of the fusewith its supplemental percussion mechanism and powder relays forignition of the bursting charge of the projectile.

Referring to Figs. 12 to 21, the casing [3k is made in one piece andhouses therein a toothed segment made of several sheets of punchedmetal, the teeth 80a of which constantly meshes with a central pinion 8|made rigid in rotation on the one hand with a central gear 82 by fiutingengagement and on the other hand with the release control drum 4| of thetime percussion.

This central pinion is journalled by its upper pivot 8Ia in the centerof casing I310 and by its lower pivot M1), the extension 8lc of whichconstitutes the firing pin. in the center of a sleeve 15 made rigid withthe time percussion mechanism holder 42. A lever 83 superposed totoothed segment 85, the function of which will be hereinafter explained,has a bellied portion 83a and a semicircular opening 83b coacting with acontact member 800 fixed on segment 80. Both the segment 80 and thelever 83 are pivoted about a common shaft 84 secured to the casing I370.

In the wall of this casing there is provided an opening 13 of a widthcorresponding to the thickness of both segment 80 and lever 83 so as topermit said lever and said segment to freely oscillate through thisopening I3 after firing under the action of the centrifugal force withinan annular groove l7 provided in the inner wall of the fuse body I.

The impact percussion device located in the front portion of the fusecomprises a bush 65 mounted, on the one hand axially slidable in therear portion 2 j of the key 2 and on the other hand with itsdiametrically slotted portion 65a. on the bar 25. This bush 65 isprovided with a firing pin 64 made rigid therewith, which iscounterweighted by a, pin 14 (Fig. 13) diametrically opposed thereto.The firing pin is maintained away from a primer 66 by the two stoplevers 23 of the balance wheel, said levers having a fork-shaped opening23b (Fig. 13) land a con 9 ical recess '230 arranged concentrically tothe firing pin 64 and to the pin 14 respectively and coaoting withcorresponding conical bevels on the flanges 66a and 14a of firing pin 54and pin M respectively.

The key 2 is bored through its whole length for housing therein a tube61 of light metal engaged on the tube 27 of the clockwork. Tube 5'!serves to transmit to bush '65 the thrust which it should receive from aplunger 68 axially slidable in the cap nut I screwed in the point of thefuse. A thin disk 69 seals the upper end of the axial bore of the capnut I.

The plunger 58 has a radial bore 68a into which there is fixed a copperwire 68b bearing against the front end of key 2 so as to counterweightthe air pressure on said plunger in case disk 59 should untimely break.

The primer 86 is lodged in a sleeve 66a placed between plates l5, I6 and20 and its burst is intensified at the time of the impact by two powderrelays, which are located the one (not shown) in the massive portion ofthe casing 13k below the primer 56 and the other 9b in the base plug 9.

At rest, before firing, bush 65 is locked against any axial movement bya ball 556 located in a radial bore 2g of key 2 and kept in operativeposition in an adjacent socket 65 in bush 55 by means of a pin lkradially adjusted in the front portion of fuse body I. This latter isprovided with an annular groove I which permits ball 65s to escape aftersetting of the fuse.

In this embodiment, safety lever l2 (Fig. 17) which co-operates beforefiring with notch Md of the release control drum is prevented fromswinging in the safety position (Fig. 17) by a lug 52k inserted in thetime percussion mechanism holder 32 and coacting with a nose lZg oflever arm I21); this latter also has another nose l'Zf engaged in notchMd with the double purpose of locking drum 4| against any untimelyangular displacement and preventing toe 45a of member 4 5 from passingthrough.

The working of the fuse shown in Figs. 12 to 2 1 after the settingthereof is the following:

Upon firing, bush 48 recoils by inertia and compresses spring 39 thusallowing segment 50 to resiliently open, while during linearacceleration bush 85, tube 6? and plunger 68 keep firing pin 56 and pinM with their tapered chamfers E ia and Ma close against the conical seat230 of lever 23 thus preventing the latter from untimely giving off.

Immediately after termination of the linear acceleration, thecentrifugal force simultaneously promotes spreading of the segment 59,balls 41, lever l2, levers 23, ball 55c, lever 83 and also of toothedsegment 80 which begins to actuate central pinion 8'! and thus the wholegear train of the clockwork and the control member 4|.

At the beginning of the flight of the projectile, during a certain lapseof time, lever 83 actuates toothed segment or rack 89 by means of thecontact member Bile (Fig. 15) thus acting as an impertant supplementaland provisional source of driving power which is necessary to securestarting of the clockwork; soon after, the bellied portion 83a of lever83 comes to strike the bottom of the groove lj (Fig. 16) thus preventinglever 83 from driving segment 80, whose center of gravity lies moredistant from the axis of the fuse so as to insure a driving moment whichis sufficient to maintain the speed of the clockwork.

This particular characteristic of the centrifugal '4 if) driving deviceis useful because it is well known that centrifugally actuated fusescannot be used in small calibre projectiles owing to the insufiicientinitial angular speed which does not allow the centrifugal force togenerate a driving moment able to start the clockwork.

The time percussion mechanism works like that of the first embodiment;when notch Md of the release control drum 4 comes to lie adjacent to toe45a of the release lever 45, primer 43a drops on firing pin Bic thuspromoting the explosion.

However, if during the fiight of the projectile the point thereofstrikes against any obstacle, the plunger '63 will receive a shock whichwill be sufficient to draw back, through the medium of tube 61, the bush65 and thus the firing pin 64 against the percussion cap 66 promotingthe explosion. of the projectile through the second powder relay 9b.

The tube 6'! formed of a thin sheet of light metal is further soweakened as to insure unfailing percussion of the primer and to alsoavoid any deformation of the plate 22 in the case of an untimely shockon the point of the fuse during carriages or manipulations.

The fuse shown in Figs. 22-26 only differs from that shown in Figs.12-21 by details and by the fact that it is more specially intended toprojectiles for automatic guns of small calibre, for example 37 to mm.Owing to the high speed of rotation of such projectiles and the value ofthe centrifugal force resulting therefrom, the cen trifugally operatedstarting lever 83 may be omitted.

The locking segments 8 of the timing position are located in acorresponding groove 2b of key 2. and made rigid in rotation therewith.These locking segments work in the same way as described in reference toboth the precedent embodiments, that is immediately after firing duringthe linear acceleration and then during the flight, under the eifect ofthe centrifugal force.

Bush 55, comprising firing pin 54 and counterweighting pin M actsdirectly as a plunger at the time of impact of the fuse point.

Finally the fuse is provided with a complementary safety means againstany untimely working of the time percussion mechanism. This meansconsists of a ball 1E1 arranged between the release lever 45 and thebottom of the sleeve l2. Before firing, this ball 19 is prevented fromescaping from its locking position into the groove N1 of the fuse bodyby an inertia pin H located midway the notch 12a of the sleeve 12 whichconstitutes the bearing of pivot 13a, of central pinion '33. In thisposition pin H locks the passage for the hall 155. This passage stillremains locked after timing and during the flight of the projec tile bythe rim of drum il until a short time before notch Md comes to lieadjacent toe 45a and permits releasing of the percussion spring 44.

It will be noted that, in Fig. 22, the section of the clockwork and ofthe percussion members, the angular position of which differs from thatshown in Fig, 12, clearly shows the high-sensitive impact percussiondevice, namely firing pin 64, counterweighting pin M, locking levers 23,primer $6 and powder relay 6611.

What I claim is:

1. A clockwork-operated time fuse for projectiles, comprising a hollowbody made in one piece, an annular groove in the inner wall of saidbody, a setting member arranged rotatably with respect to said body, aclockwork casin made in one piece rotatably mounted in said fuse bodyfor unrestrained angular displacement in either direction, meanscoupling said casing to said setting member for rotation thereby,centrifugally actuated means operable on firing of the projectile forlocking said setting member and said casing against rotation withrespect to said fuse body, said casing including an integral bodyportion with a median transverse wall separating two chambers, the upperchamber housing the gear train of the clockwork, the balance and theescape wheel; the lower chamber housing a centrifugal drivin member foractuating the clockwork and a rotating control member, said centrifugaldriving member being adapted to swing under the action of thecentrifugal force after firing and to project through an openingprovided in the casing into the annular groove of the fuse'body; inertiaresponsive means operative on firing for locking said centrifugaldriving means and cooperating balance during the linear acceleration ofthe projectile, said inertia means releasing said balance when thelinear acceleration ceases, and a time percussion assembly within saidhollow fuse body adjacent said clockwork casing, said time percussionassembly including a primer holder, a primer seated in said holder andmeans cooperating with said control member to detonate said primer uponrotation of said control member into a predetermined angular positionwith respect to said time percussion assembly.

2. A clockwork-operated time fuse as claimed in claim 1 comprising incombination a driving shaft having a median toothed pinion, acentrifugal driving member in mesh with said pinion, a gear on theforward end of said shaft for driving the gear train of a clockwork, arotatable control drum rigidly secured to said shaft at the rear of thepinion, and bearing means pivotally supporting said shaft, the rear endof said shaft projecting beyond its associated bearing means toconstitute a fixed firing pin.

3. A clockwork-operated time fuse as claimed in claim 1, comprising incombination a driving shaft having a median toothed pinion, acentrifugal driving member including a first pivotally mounted leverhaving an inwardly toothed segment meshing with said median pinion ofthe driving shaft and a second driving lever pivoted co-axially with thefirst lever and adapted to swing under the action of the centrifugalforce, said second lever having an arcuate slot adapted to cooperatewith a contact member fixed on said first lever to form a one-waycoupling, whereby said second lever acts at the beginning of the flightof the projectile as a starting member to increase the driving momentand thus facilitate the starting of the clockwork, a gear on the forwardend of said driving shaft for driving the gear train of the clockwork, arotatable control drum rigidly secured to said shaft at the rear of thepinion, and bearing means pivotally supporting said shaft, the rear endof said shaft projecting beyond its associated bearing means toconstitute a fixed firing pin.

4. A clockwork-operated time fuse for projectiles comprising a hollowbody made in one piece, an annular groove provided in the inner wall ofsaid body, setting means arranged rotatably with respect to said body; aclockwork casing rotatably mounted in said fuse body and coupled withsaid setting means for rotation thereby; detonation timing mechanismwithin said casing including a centrifugal driving member for rotatingan axially arranged shaft carrying a release control drum, the lower endof said driving shaft constituting a fixed firing pin; a time percussionmechanism located immediately underneath said firing pin; said timepercussion mechanism comprising a safety and stop lever adapted tocooperate with the rotating release control drum, a flanged sleeve, aprimer holder slidably mounted in said sleeve, a release lever securedto said primer holder for cooperation with said release control drum, aspring-pressed bush slidably mounted on said sleeve, a percussion springadapted to upwardly urge said primer holder, means for locking saidpercussion mechanism before firing; and an auxiliary high-sensitiveimpact percussion device housed in the front portion of the fuse, saiddevice comprising a primer lodged within the clockwork casing, at leastone powder relay for ignition of the bursting charge of the projectile,

, a recoil bush arranged axially in the point of the fuse body andadapted to run back by impact, a firing pin rigidly fixed eccentricallyto the lower end of said recoil bush, and centrifugally released meansfor locking. said impact percussion device before firing.

5. A clockwork-operated time fuse as claimed in claim 4, wherein thelocking means of the auxiliary impact percussion device is constitutedby two centrifugally actuated stop levers journalled on the upper plateof the clockwork and adapted to cooperate with the firing pin forWithholding it from the primer before firing and during the linearacceleration of the projectile.

6. A clockwork-operated time fuse as claimed in claim 4 comprising incombination a safety ball interposed between the release lever and thebottom of the release control drum, said drum having a notch in the wallthereof through which the ball rolls under the action of the centrifugalforce, and an inertia-released member blocking movement of said ballthrough said notch prior to the firing of the projectile.

FERNAND DELAY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,102,732 Faber July 7, 19141,665,899 Varaud Apr. 10, 1928 1,890,552 Varaud Dec. 13, 1932 2,097,836Junghans Nov. 2, 1937 2,149,470 Schank Mar. 7, 1939 2,164,115 LasserreJune 27, 1939 FOREIGN PATENTS Number Country Date 134,398 SwitzerlandOct. 16, 1929 414,191 France June 13, 1910 824,395 France Nov. 10, 1937828,511 France Feb. 14, 1938

